OBJECTIVETo explore the clinical significance of serum anti-ryanodine receptor (RyR) antibody in the diagnosis of myasthenia gravis (MG).

METHODSThe crude sarcoplasmic reticulum was prepared from rabbit skeletal muscle, and then purified by differential centrifugation to produce the antigen. The serum anti-RyR antibody levels in 74 patients with MG (including 21 patients with comorbidic thymomas) were determined with ELISA.

RESULTSWestern blot demonstrated the presence of RyR in purified crude sarcoplasmic reticulum. The positive rate of anti-RyR antibody was significantly higher in MG patients who had comorbidic thymoma compared with those who had no such comorbidity (P < 0.01). Also, the positive rate was closely correlated with the severity of MG.

CONCLUSIONSerum anti-RyR antibody test is helpful in the diagnosis of MG associated with thymoma and can be used to judge the outcome of MG.

Autoantibodies ; blood ; Humans ; Myasthenia Gravis ; blood ; complications ; immunology ; Ryanodine Receptor Calcium Release Channel ; immunology ; Thymoma ; complications ; Thymus Neoplasms ; complications

For the purpose of investigating the pattern of E-cadherin (E-CD) expression in thymomas, 72 cases were immunostained using monoclonal antibody (HECD-1) and microwave-enhanced immunohistochemical method on formalin-fixed, paraffin-embedded tissue sections. The thymomas were classified according to modified Muller-Hermelink classification. The spindle-shaped, medullary type tumor epithelial cells in medullary (3 cases) and composite type (20 cases) thymomas rarely expressed E-CD except in focal areas showing microcystic change observed in 8 cases. Meanwhile, the cohesive epithelioid tumor cells in every case of well-differentiated thymic carcinomas (WDTC) (29 cases) expressed E-CD. The epithelial cells in cortical type (13 cases) expressed stronger E-CD compared with those of organoid type (7 cases). In cases of WDTC admixed with cortical type, we observed increasing expression of E-CD as the tumor epithelium forms cohesive sheets. We could not find any loss of E-CD expression in invasive foci of the 11 cases of high-staged WDTC examined. Since the results of our study show a strong correlation between E-CD expression and epithelioid morphology of the tumor, E-CD seems to play a major role as a morpho-regulatory factor rather than as a suppressor of invasion in organotypic thymomas.
Adolescence ; Adult ; Aged ; Cadherins/immunology ; Cadherins/analysis* ; Female ; Human ; Immunohistochemistry ; Male ; Middle Age ; Neoplasm Staging ; Thymoma/pathology ; Thymoma/classification ; Thymoma/chemistry* ; Thymus Neoplasms/pathology ; Thymus Neoplasms/classification ; Thymus Neoplasms/chemistry*

OBJECTIVETo study the clinical significance of serum anti-titin antibody level in the diagnosis of myasthenia gravis (MG) with thymoma.

METHODThe serum anti-titin antibody was analysed by ELISA method in 40 cases of health control group, 90 cases of MG, 17 cases of MG with thymoma and 7 cases of no-MG thymoma. The positive rate was compared among these groups.

RESULTSThe positive rate of anti-titin antibody was significantly higher in MG with thymoma patients than MG patients (94% and 3%, P < 0.01). According to the Osserman's classification, anti-titin antibody was present mostly in patients (43%) in IV stage, and also present in 2 cases of 7 who with no-MG thymoma.

CONCLUSIONSerum anti-titin antibody test is helpful in the diagnosis of MG with thymoma.

Adolescent ; Adult ; Aged ; Antibodies ; blood ; Connectin ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Middle Aged ; Muscle Proteins ; immunology ; Myasthenia Gravis ; complications ; diagnosis ; immunology ; Protein Kinases ; immunology ; Thymoma ; complications ; diagnosis ; immunology ; Thymus Neoplasms ; complications ; diagnosis ; immunology

BACKGROUNDAntibodies against acetylcholine receptor, acetylcholinesterase, ryanodine receptor and titin have been found in patients with myasthenia gravis. However, the relations between these antibodies and character of myasthenia gravis are unknown. This study aimed to detect multiple antibodies in myasthenia gravis and to investigate its clinical significance.

METHODSThese antibodies were detected by enzyme-linked immunoabsorbent assay in 89 cases of myasthenia gravis, 66 cases of other neurological diseases and 66 healthy controls. The incidences of antibodies were compared using the chi-square test.

RESULTSAcetylcholine receptor, acetylcholinesterase, titin and ryanodine receptor antibodies were detected in 53.9%, 20.2%, 64.0% and 55.0% of myasthenia gravis patients respectively, higher than in patients of other neurological diseases and controls groups. The combination of the four antibodies assays provided 94.4% sensitivity and 84.0% specificity for the diagnosis of myasthenia gravis. Acetylcholinesterase antibody occurred more frequently in acetylcholine receptor antibody negative patients with adverse reactions to neostigmine test. Titin antibody provided 82.1% sensitivity and 52.5% specificity for myasthenia gravis with thymoma. Incidences of titin and of ryanodine receptor antibody were higher in late onset myasthenia gravis than in early onset myasthenia gravis. The proportion of titin antibody positive patients increased with the severity of myasthenia gravis as graded by a modified Osserman scale.

CONCLUSIONSTesting for acetylcholine receptor, acetylcholinesterase, titin and ryanodine receptor antibodies can offer a better diagnostic method for myasthenia gravis than each antibody test alone. Titin antibody combined with computed tomography was better for the diagnosis of thymoma. Titin antibody occurred most frequently in severe myasthenia gravis.

Adult ; Age of Onset ; Antibodies ; metabolism ; Case-Control Studies ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Middle Aged ; Myasthenia Gravis ; immunology ; metabolism ; pathology ; Thymoma ; immunology

The cell surface molecule identified by a monoclonal antibody(TE-1) to human thymic epithelial cell showed the specificity for thymic epithelial cells of both the cortex and medulla. TE-1 reacted with the epithelial cells of normal thymus and thymoma in fresh frozen tissues. The antigen recognized by TE-1 was mostly confined to the cell surface membrane and arranged in reticular network with long processes between thymocytes. On immunohistochemical analysis, TE-1 did not recognize normal epithelial cells of the uterine cervix, skin and stomach, and neoplastic cells of squamous cell carcinoma and gastric adenocarcinoma, all of which were stained with anti-cytokeratin monoclonal antibody. Among the tumor cell lines tested with flow cytometry, most of epithelial and all of hematopoietic cell origin were not labeled with TE-1. In summary, TE-1 appears to be a monoclonal antibody against a surface antigen of human thymic epithelial cell that is immunohistologically different from known epithelial cell surface antigens reported so far.
Animals ; Antibodies, Monoclonal/biosynthesis/*immunology ; Antibody Specificity ; Antigens, Surface/*immunology ; Epithelium/immunology ; Fluorescent Antibody Technique ; Humans ; Immunoenzyme Techniques ; Immunoglobulin G/immunology ; Immunoglobulin Isotypes/immunology ; Mice ; Mice, Inbred BALB C ; Neoplasms/immunology ; Thymoma/immunology ; Thymus Gland/*immunology ; Thymus Neoplasms/immunology ; Tumor Cells, Cultured

Good's syndrome is extremely rare. This adult-onset condition is characterized by a thymoma with immunodeficiency, low B- and T-cell counts, and hypo-gammaglobulinemia. The initial clinical presentation is either a mass-lesion thymoma or a recurrent infection. Patients with Good's syndrome are very susceptible to infections; common respiratory and opportunistic infections can be life-threatening. There are no reports of granulomatous lung disease in patients with Good's syndrome, although it has been observed in patients with common variable immunodeficiency, of which Good's syndrome is a subset. We describe a 53-year-old male thymoma patient who presented with respiratory symptoms caused by granulomatous lung disease and an opportunistic infection. He died of uncontrolled fungal infection despite repeated intravenous immunoglobulin and supportive care. Clinicians should look for evidence of immunologic dysfunction in thymoma patients presenting with severe recurrent infections, especially opportunistic infections.
Fatal Outcome ; Granuloma, Respiratory Tract/diagnosis/*etiology/therapy ; Humans ; Immunologic Deficiency Syndromes/*complications/immunology/pathology ; Lung Diseases/diagnosis/*etiology/therapy ; Male ; Middle Aged ; Thymoma/*complications/immunology/pathology ; Thymus Neoplasms/*complications/immunology/pathology

Adult ; Antibodies, Monoclonal ; analysis ; DNA Nucleotidylexotransferase ; metabolism ; Female ; Follow-Up Studies ; Humans ; Keratins ; immunology ; Male ; Middle Aged ; Prognosis ; Thymoma ; metabolism ; pathology ; surgery ; Thymus Neoplasms ; metabolism ; pathology ; surgery

Cutaneous nocardiosis, which usually manifests in the form of pustules, abscesses, or subcutaneous nodules, is occasionally found in immunocompromised patients. A 59-yr-old Korean man with myasthenia gravis and thymoma developed nodular skin lesions on his trunk. Histopathologically, abscess formation with a dense infiltrate of neutrophils and many cytophagic histiocytes were observed. Numerous filamentous organisms, which turned out to be Nocardia asteroides by culture, were also found. After sulfamethoxazole-trimethoprim therapy, all of the skin lesions rapidly decreased in size, with a marked diminution of the number of cytophagic histiocytes, and cleared up within four months. On reporting a case of cutaneous nocardiosis showing unusual histopathologic findings, we considered that reactive conditions should be included in the differential diagnosis of the cutaneous cytophagocytosis, and that nocardiosis could be one of the diseases showing reactive cytophagocytosis.
Anti-Bacterial Agents/therapeutic use ; Histiocytes/*immunology ; Humans ; Male ; Middle Aged ; Myasthenia Gravis/complications ; Neutrophils/*immunology ; Nocardia Infections/drug therapy/*immunology/microbiology/pathology ; Nocardia asteroides/drug effects/*immunology/isolation & purification ; Phagocytosis/*immunology ; Skin Diseases, Bacterial/drug therapy/*immunology/microbiology/pathology ; Thymoma/complications ; Thymus Neoplasms/complications ; Treatment Outcome ; Trimethoprim-Sulfamethoxazole Combination/therapeutic use

OBJECTIVETo investigate the clinical significance of the serum anti-titin, anti-ryanodine receptor (RyR) antibody level and thymus CT scan in the diagnosis of myasthenia gravis with thymoma.

METHODSTotally 32 patients with myasthenia gravis who had received thymectomy were included in the study. Abnormalities were shown under CT scan of thymus in all these patients. The relationships were studied among the pathological diagnosis, CT findings, and serum level of thymoma associated antibodies: anti-titin and anti-RyR antibodies.

RESULTSThe pathological diagnosis of thymoma was made in 21 patients and thymus hyperplasia in 11 patients after operation. The sensitivity of CT scan in the diagnosis of thymomas was 90.5%, the specificity of serum thymoma associated antibodies in the diagnosis of thymoma was 100%.

CONCLUSIONThe thymoma-associated antibodies test is helpful in the differential diagnosis of thymomas and thymus hyperplasia; when combined with CT scan, it may achieve high sensitivity in the diagnosis of the thymoma.

Adult ; Antibodies, Neoplasm ; blood ; immunology ; Autoantibodies ; blood ; Biomarkers, Tumor ; blood ; Female ; Humans ; Male ; Myasthenia Gravis ; complications ; diagnostic imaging ; immunology ; Ryanodine Receptor Calcium Release Channel ; immunology ; Thymoma ; complications ; diagnostic imaging ; immunology ; Thymus Hyperplasia ; diagnostic imaging ; immunology ; Thymus Neoplasms ; complications ; diagnostic imaging ; immunology ; Tomography, X-Ray Computed

OBJECTIVETo study the expression of CD20 in thymomas and its clinical significance.

METHODSOne hundred and seventy-nine cases of thymoma were enrolled into the study. The histologic diagnosis was reviewed by two experienced pathologists on the basis of the 2004 WHO classification. One hundred and two cases were selected for immunohistochemical study for CD20, pancytokeratin, TdT, CD3, CD43, CD99 and S-100 protein. The cases were further categorized into two groups, according to the association with clinical evidence of myasthenia gravis. The immunostaining pattern was then statistically analyzed.

RESULTSAmongst the 102 cases studied, 7 cases belonged to type A thymoma, 32 cases type AB thymoma, 17 cases type B1 thymoma, 15 cases type B2 thymoma, 17 cases type B3 thymoma and 14 cases thymic carcinoma. The expression rates of CD20 in neoplastic epithelial cells of type A, type AB, type B1, type B2 and type B3 thymomas and thymic carcinomas were 3/7, 84.4% (27/32), 1/17, 2/15, 0/17, 0/14, respectively. The proportions of CD20-positive lymphocytes in the background were 3/7, 18.8% (6/32), 14/17, 11/15, 11/17, 6/14, respectively. The proportion of CD20-positive intra-tumoral B lymphocytes in the group of thymomas with myasthenia gravis was 67.5% (22/40), in contrast to 35.5% (22/62) in those without myasthenia gravis.

CONCLUSIONSThe neoplastic epithelial cells in cases of type A and type AB thymoma, as well as few cases of type B1 and B2 thymoma, express CD20. The immunostain highlights the presence of oval, stellate or spindly cells. Thymomas associated with myasthenia gravis contain a significant population of CD20-positive intra-tumoral B lymphocytes. Type AB thymomas may be originated from different populations of cells, rather than a simple admixture of type A and B thymoma cells.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antigens, CD20 ; metabolism ; B-Lymphocytes ; immunology ; pathology ; Child ; Epithelial Cells ; immunology ; pathology ; Female ; Humans ; Male ; Middle Aged ; Myasthenia Gravis ; complications ; immunology ; pathology ; Thymoma ; classification ; complications ; immunology ; pathology ; Thymus Neoplasms ; classification ; complications ; immunology ; pathology ; Young Adult